This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
Pulmonary complications, such as pneumonia, respiratory failure, bronchospasm, collapsed lung segments (atelectasis) and pleural effusion, are among the most common problems after surgery and lengthen the hospital stay. The ARISCAT score, also called the Canet risk index after its first author, was derived in 2010 from 2,464 patients in 59 Catalan hospitals. It uses seven factors known before or during surgery.
The points
| Factor | Points |
|---|---|
| Age 51 to 80 | 3 |
| Age over 80 | 16 |
| SpO2 91 to 95% on room air | 8 |
| SpO2 90% or less | 24 |
| Respiratory infection in the last month | 17 |
| Preoperative anemia (Hb 10 g/dL or less) | 11 |
| Upper abdominal incision | 15 |
| Intrathoracic incision | 24 |
| Surgery lasting 2 to 3 hours | 16 |
| Surgery lasting more than 3 hours | 23 |
| Emergency procedure | 8 |
The site of the incision and the length of the operation weigh as much as the patient’s own condition: an upper abdominal operation of more than three hours already scores 38.
Example
A 65-year-old (3) having an elective upper abdominal operation (15) expected to last 2 to 3 hours (16), with normal saturation and no recent infection, scores 34: intermediate risk, with pulmonary complications in about 13% of similar patients.
Risk categories
| Score | Risk | Complications in the derivation study |
|---|---|---|
| under 26 | low | 1.6% |
| 26 to 44 | intermediate | 13.3% |
| 45 or more | high | 42.1% |
What to do with the result
For intermediate and high risk patients, teams plan lung-protective ventilation during anesthesia, careful pain control (often regional), early mobilization, breathing exercises or incentive spirometry, and they treat a recent chest infection or anemia when surgery can wait. Postponing elective surgery for a month after a respiratory infection removes 17 points.
Limits
ARISCAT was validated in a large European cohort (PERISCOPE), where it kept good accuracy, but the absolute rates vary with how complications are defined. It does not include smoking, COPD or obstructive sleep apnea, which also matter; the STOP-Bang questionnaire screens for sleep apnea.